ISTerre seminar

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On strain rates and shear zones and fractures in lava domes

Wednesday 1 April 2026 - 14h00

Catherine Mériaux - East African Institute for Fundamental Research / University of Rwanda
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Lava domes are volcanic structures formed by the eruption of highly viscous lava. These domes are associated with deadly volcanic hazards because they can become unstable and collapse, generating dense pyroclastic flows that propagate at high speeds. The conditions leading to dome destabilization remain poorly understood. Most explanations invoke an increase in gas overpressure within the lava, but do not specify how or at what stage of dome growth, failure occurs. This study examines how lava that accumulates above a vent and extends laterally is subjected to significant strains that can induce failure. In this talk, I will present and discuss the results of three-dimensional numerical simulations showing the pressure and strain distribution in lava spreading over a horizontal surface away from a vent, with an emphasis on the characteristics and location of shear zones and fractures that may develop and at what stage of growth.

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Organizing team : Géophysique des volcans & géothermie

Salle Paul Gidon, Bâtiment Belledonnes, 73376 Le Bourget-du-Lac

Informations de visio :

https://univ-grenoble-alpes-fr.zoom.us/j/97093351215?pwd=ZJtkyZ1DNg84ispczTPVGIPxKW2Mhb.1